Statistical Methods
The statistical analyses were performed with IBM SPSS Statistics V.22.0
(SPSS Inc, Chicago). Continuous variables were summarized as means±SDs
for normal distribution data and as median (interquartile range) for
abnormal distribution data. Independent-samples t test (for normal
distribution data), Mann-Whitney U tests (for abnormal distribution
data), or Chi-square (for categorical variables) was used to compare
parameters in the two groups. Proportions were compared using the χ2
test or by linear-by linear χ2 association test in case of ordinal
categorical variables. Univariate and multivariate analyses were
performed to analyze the influence of each factor on PICU mortality. The
ability of factors to predict hospital mortality was tested using
receiver operating characteristic
(ROC) curve performed using STATA 15.0 MP (College Station, Texas, USA).
Cut-off values were identified using the highest Youden index
(sensitivity + specificity-1)[11]. Significance
was taken as a P value less than 0.05.